In case you haven't heard, the 21-year-old actor is reportedly engaged to his girlfriend of six months and Magic Mike costar Riley Keough. And while we were a little surprised by the news, Joe Manganiello, who's also in the film, says he definitely saw romance brewing between the lovebirds while on the set of the upcoming stripper flick.

Manganiello also has some ideas for how to celebrate the end of Pettyfer's life as a bachelor. Cue the G-strings!

"That's what I hear," Manganiello told me of the engagement at the Human Rights Campaign Gala in L.A. "If that's true, then I'm very happy for them...I love both of them."

Manganiello hasn't spoken to Pettyfer since the engagement news broke, but isn't surprised since he saw the twosome's chemistry while making the film. "I think we all did," he said.

As for a bachelor party, Manganiello joked that a Magic Mike stripper-themed bash might work a little better for a female audience. "It would be a bachelorette party I guess," he laughed. "Maybe we'll all take turns giving Riley lap dances."

How about his and hers G-strings as gifts?

"I think they already have them from the movie," he smiled. "So maybe we can just call the costume department and bust them back out."